Plant regulators



United States Patent PLANT REGULATORS Samuel B. Soloway and Juan G.Morales, Denver, 'Colo., and Johannes Van Overbeek, Modesto, 'Calif.,assignors to Shell Development Company, New York, N. Y., a corporationof Delaware No Drawing. Application March 14, 1955, Serial No. 494,279

'19 Claims. (Cl. 71-2.6)

This invention pertains to novel compositions useful as plant regulatorsand to their use for regulating, modifying, or controlling the growthprocesses of living plant tissue. More particularly, the presentinvention pertains to novel compositions, useful for agriculturalpurposes, comprising a new chemical type of plant regulator as an activecomponent, and to the method for regulating the growth processes ofliving plant tissues by application of the novel compositions to theplants or plant tissue.

It is well known that certain chemical compounds have the capacity toinduce elongation of the shoot cells of growing plants, as well as toaffect other growth processes of the living plant. Illustrative auxins,as these chemical compounds are generally known, include the naturallyoccurring auxin indole-3-acetic acid and also such well-known syntheticplant regulators as 2,4-dichlorophenoxyacetic acid (2,4D),2,5-dichlorobenzoic acid (2,5-B), alphanaphthaleneacetic acid (NAA),2,4,5-trichlorophenoxyacetic acid (2,4,5-T), and others.

In accordance with the present invention there has been discovered a newchemical type of plant regulator. Surprisingly, the new regulators ofthis invention generally exert an action on plants that is distinctlydifierent from the effects of the foregoing and similar known plantregulators. Instead of inducing cellular elongation of the shoots ofgrowing plants, the plant regulators of this invention tend to suppresscell elongation. Applied in appropriate amounts to the foliage of livingplants, the new growth regulators of this invention tend to inducedefoliation of the plant, rather than to inhibit it as do the auxin-likeplant regulators, notably 2,4-D and NAA. Whereas the auxin-like plantregulators when applied in suitable concentrations tend to promote rootdevelopment, as, for example, on cuttings, the new regulators of thisinvention when similarly applied tend to suppress the development orgrowth of roots. In general, the novel regulators of this invention tendto produce effects opposite to those induced by indoleacetic acid,naphthaleneacetic acid, and other auxin-like plant regulators which ingeneral promote growth, and, therefore, the new plant regulators of thisinvention exert what may be termed an anti-auxin eflfect.

The new chemical type of plant regulator that is provided by theinvention comprises certain substituted aliphatic carboxylic acids andthe anhydro derivative of these acids. These substituted acids, and theanhydro derivatives thereof, all are characterized by the substitution,on the aliphatic acid residue, of a bicyclic, unsaturated,cycloaliphatic, fused-ring nucleus comprising two fused pentatomiccarbocyclic rings having three carbons "ice in common. According to apreferred aspect of the invention the bicyclic fused-ring nucleus issubstituted by one or more atoms of halogen, preferably a plurality ofatoms of chlorine and/or bromine. Although the bicyclic fused-ringnucleus may contain one or more hydrocarbon substituents containingpreferably a relatively low number of carbon atoms, in the preferredactive agents of the invention the nuclear halogens are present as theonly substituents on the carbon atoms which form the bicyclic fused-ringnucleus.

Experiments have demonstrated that, as is true with2,4-dichlorophenoxyacetic acid, naphthaleneacetic acid, and other knowngrowth promoters, anhydro derivatives of the above-defined class ofsubstituted acids exert physiological efiects upon plants, although inall cases not in a manner fully equivalent to the substituted acids perThe anhydro derivatives are, generally speaking, the

derivatives of the acids which can be regarded as being regarded asbeing in the hydrated form-C(OH)3) with an organic compound containinghydroxyl attached to carbon or with a base, with consequent eliminationof water. Anhydro derivatives which have been employed in novelcompositions of the invention for regulating the growth of living plantsor plant tissues include salts of inorganic bases, such as alkali metaland alkaline earth metal salts, salts of amphoteric metals, ammoniumsalts and hydrazine salts; salts of organic bases, such as amines;esters, including esters of simple monohydric alcohols as well as thoseof polyhydric alcohols, of substituted aliphatic alcohols and also ofphenols; amides, both N-substituted and N-unsubstituted; and imidoderivatives, such as imido-ethers or imidates, and imido-amides, oramidines.

Although physiological activity with respect to plants and plant tissuesthus broadly characterizes the novel plant regulators of this invention,it has been found that the esters, the salts, and especially the acidsper se generally are the most efiective of the novel regulators,especially when applied to mature plants. In the preferred compositionsof the invention the active agent is present in the ionizable formrepresented by the substituted carboxylic acid per se or a salt of theacid, for example, an alkali metal or nitrogen-base salt.

The following examples will serve to illustrate the invention in one ormore of its novel aspects as it pertains to novel plant regulators, tonovel compositions containing the same and suitable for use foragricultural or horticultural purposes, and to the regulation,modification, control, prevention, or eradication of plant growth byapplication to the living plant or plant tissue or its environment.

In one series of tests, the physiological activity of the novel plantregulators of the invention was illustrated with respect to defoliationof peach trees. In these tests, branches of mature Elberta peach treesfield-grown in the San Joaquin Valley of California, were sprayed withmeasured concentrations of the materials to be tested. Emulsions wereprepared by mixing a xylene or acetone solution of the material to betested with diesel oil and emulsifying one volume of the concentrate ineight volumes of water with the aid of an oil-soluble emulsifying agent(0.2% B 1956, a low molecular weight glycero1- p hthalic esteremulsifying agent sold by Rohm and Haas Company, and 0.2% ylene oxidereaction Triton X-100, an alkylphenolethproduct sold by Rohm and HaasCompany), or by similarly emulsifying in water a solution of the testmaterial in petroleum distillate having were observed.

TABLE I Concentration Ex. ,of active {Percent No. Activeagent agentindefoliaspray, 'tion gms. perliter 1- 1,4,5,6,7,7 -,hexachlorobicyelo(2.2.1) -.5 hep 0. 36 10D 'tene2-acetic'acid. 2. .1 ,4,5,6;'? ,7-,hexachlorobicyclo (2.2.1) 5 hep 3.5 100 .tene-2-carboxylic acid, M. P.176-8" 0. 1.75 80 4. 1',4,5,6- tetrac 0b y 010 (2.2.1) --hepte11e- 1. 420 ;2 -car.bpxylic acid. 5. '1,4,'5;6,7,7 -hexachlorobicyclo (2.2.1) 5-hep 1.9 100 tene-Z-acrylic acid. 6.-.. 1,,4, 5,6,7,7 -hexachlorobicyclo(2.2.1) -5-hep- 1. 9 86 tene-Z propionic acid. 7-... 1,4,5,6,77-.hexach1orobicyclo (2.2.1) -,5-,hcp- 2. 50

. .tene pelargonie acid. 8... 1,4,5,6- etrachlorobicyclo (2.2.1)-5-heptene- 1. 4 20 '2ecarboxylic acid, M. P. 138-510" C. 9.Bieycl0(2.2.1)-5-heptene 2-carboxylic acid.... 0. 14. 40 10- Ethyl'1,4,5,6,7,7-hexachlorobicyclo (2.2.1)-5- 2; 1 '85 Iheptene-2-acetimidate hydrochloride. 1 1--- Eth l .1,4,5,6,7.7hexachlorobicyclo(2.2.1)- 2.3 90

' 5-heptene-2-acetim1date hydrobromidc. 12- lsopropyl 1,4,5,6,7,7hexachlorobicyclo 2. 2 55 (2.2.1)-5-heptene-2-acctimidate hydrochloride. 13--- Methyl 1,4,5,6,7,7-hexachlorobicycl0(2.2.1)- 2.0 85

5-heptene-2-acetimidate hydrochloride. 14--. Ethyl1,4,5,6,7,7-hexachlorobicyclo(2.2.1)- 2:3 40

V 5 heptene-2'carb0ximidatehydrochloride. 15--- Ethylalpha-cyano4,4,5,6,7,7-hexachlorobi- 0. 42 95cyclo(2.2.1)-5-heptene-2-acrylate. 16.-- Ethylalpha-cyano-1,4,5,6-tetrachlorobicy- 0.25 100clo(2.2.1)15-heptene-2-acrylate. 17--. Ethyl 'alpha-cyanobic'clo(2.2.1)-5-heptene- 2. 2

2-acrylate. 1S..- Ethyl 1,4,5,6,7,7-hexachlorobicyclo(2.2.1)-5- 1.9 80

heptene-2-acetate. 19- Sodium 1,4,5,6,7,7-hexachlorobicyclo(2.2.1)- 25-heptene-2-carboxylate. 20--- Sodium 1,4,5,6,7,7 hexachlorobipercent 0.005 l 100 cyclo(2.2.1)-5-heptene-2-acetate. 21--- Sodium bicyclo(2.2.1)5 heptene- (10-.-. 0.1 9 70 2 acetate. 22- Control test 0 lfests carriedout by immersing cut end of peach branch in aqueous solutionat indicatedconcentration.

In a second series of tests, the effects of plant regulators of theinvention upon the germination of seeds was determined. The tests werecarried out under standardized conditions in the greenhouse.

Seeds of the tests species of plant were planted in sterilized loamyfield soil in-3 inch porous claypots. After planting, thesoil in eachpot was sprayed with an aqueous dispersion prepared by emulsifying ordispersing the active agent in water at concentrations of 500 and 50 mg.dispersion,

per 100 cc. of the using a water-soluble emulsifying agent (Santomerse,an aromatic sulfonate emulsifying agent produced by Monsanto ChemicalCompany) to i Twenty cubic centimeters 'of the dispersion was sprayeduniformly on eifecting dispersion of the active agent.

the surface of the soil in each pot; treatment were judged byobservation of seedlings, if any, that germinated.

table, killing or severe stunting at aid in The efiects of the of thecondition I In the following the lower of the two concentrations isindicated by the numeral 1, killing or severe stunting only at thehigher of the two test concentrations is indicated by the numeral 2, andonly mild toxicity at the test concentrations is indicated by'thenumeral 3. A dash indicates no test was made.

TABLE II Oats Radish Cotton Ex. Active agent (Avena (Raph- (variety No.sutiva) anus Acala sativus) 4-42) 23..-. 1,4,5,6,7,7-hexachlorobiryclo(2.2.1)- 5- 2 1 heptene-2-acrylic acid 24..--1,4,5,6-tetrachlorobicyclo(2.2.1) -5- 3 3 heptene-2-acrylic acid. 25..--1,4,5,6,7,7-hexach1orobicyclo(2.2.1) 5- 2 2 heptene-2-acetic acid.26..-. 1,4,5,6,7,7-hexachlorobicyclo(2.2.1) 5- 1 2 heptene-2-carboxylicacid, I. 1768 27..-. Bicycln(2.2.1)-5-heptene-2-acetic acid... 3 328..-- 1,4,5,6,7,7-hexachlorobicyclo(2.2.1) 5- 2 2heptene-2-protililonic acid. 29..-- 1,4,5,6,7,7-hexac orobicyclo(2.2 1)5- 1 1 heptene-2-carboxylic acid, crude. 30..--1,4,5,6,7,7-hexachlorobicyclo(2.2.1) 5- 1 2 heptenc-2-aczylic acid, M.P. 120.5-

121C. 31...- 1,4, 5,6,7,7-a1pha,beta-octach1nrobicy- 2 3 clo (2.2.1)-5-heptene-2-propionic acid 32.. 1,4,5,6-tetrachlorobicyclo(2.2.1) -5- 2heptene-Q-carboxylic acid. M. P. 138-'40C.' 33...- 1,4,5,6,7,7hexachloro 3 methylbi- 3 2 cyclo(2.2.1) 5 heptene 2 carboxylie acid.34..-- 1,4,5,%5,7,7 hexaclllorobicyclo (2.2.1) 5- 2 2heptene-Z-carboxylic acid anhydride. 35...- Methyl1,4,5,6-tetrachlorobicyclo- 2 1 v (2.2.1) -.5 heptene 2 -.carboxylate,Ml. 86.5-87 C. 36..-; :Methyl -1,51,5,6tetrachlorobicyclo- 2 1 (2.2.1) 5-,h,eptene 2 carboxylate,

Ml. .0. 37-.-- Biityl 1,4,5,6,7,7 hexachlorobicyclo- 3 3 (2.2.1) -'5heptene 2 carboxylate. 38.... 2 actamidoethyl 1,4,5,6,7,7 hexa- 3 3 I.chlorobicyclo(2.2.1) fi -heptene 2 carboxylate. 39..-- 2 ldiethylaminoethyl 1,4,5,6,7,7 hex 3 3 achlorobicyclo -(2.2.1) 5 heptene2-carboxylate. 40.... 1,4,5,6,7,7-'hexachlorobicyclo(2.2.1) 5- 2 2heptene-2-acrylonitrile. 4.1.... (1,4,5,6,7,7 hexachlorobieyclo(2.2.1) 32 "5 hepten 2 yl methylene) malo- .nonitrile. 42...- Ammoniuml,4,5,6,7,7-hexachlorcbicy- 2 2 'cl0'(2'.2.1)-5-heptene-2-carboxylate.5.... Potassium 1 4,5,6,7,7-hexach1orobiey- 2 2 .cl0(2.2.1)-5-eptene-2-earbcxylate. 44..-- Zinc1.4,5,6,7,7-hexachl0r0bicycl0(2.2.1)- 22 I5-heptene-2carb0xylate. 45..-- N-(2-hydroxyethybammonium 1,4,5,- 2 26,7,7-hexach l0robicyclo(2.2.1) -5-hep- .tene-Zcarboxylate. 46..-.-Hydrazinium 1 4,5,6,7,7-hexach10r0bi- 3 2 'cyelo(2.2.1)-5heptene-2-carboxylate.

Example 47.In a third series antagonism bet-ween the action of robicyclo2.2.1 5,-heptene-2-acetic of experiments, the ,5, 6,7,7-hexachloacid andknown auxin-like materials was determined by observation of the ts of hetest materials on the growth of isolated pea In each test, fivesections, about 0.5 cm.

solution containingthe material to 18 hours at ambient temperature.

The growth was determined by p from the stems of pea seedlings, Pisiumih (Ala sl;a variety), were immersed in a buffer be tested for aboutvisual measurement of the length of the sections before and after the 18hour pe od The follow ng results were obtamed:

TABLE III Experi- Percent ment' Test solution increase "-No. in'lerigthButter solution B 37 Buffer solution+5 parts per million of 1,4,5,6 7 7-.15

' hexachlorobicyclo(2.2.1)-5-heptene-2-acetic ac d.

Bufler solution-[10.05 parts per million of -2,4-.di- .65chlorophenoxyacetic acid. Bufier solution+1 part per million of2,5-dichloro- 46 benzoic acid.

5 Bufier solution+5 parts per million of 1,4,5,6,7,7- 18hexachlorobicyclo(2.2.1) 5-heptene-2-acetic acid and 0.05 parts permillion of 2,4-dichlorophenoxyacetic acid. 6 Bufiersolution+5 parts permillion of 1,4,5,6,7,7- 17 achlorobicyclo(2.2.1)-5-heptene-2-acetio acid1 part er million oi2,5-dichlorobenzoic acid.

acontrol. Represents'native'growth of the .pea sections. Composiwatercontaining 1% 'of sucrose.

From a comparison of experiments 1 and 2, it is seen that 1,4,5,6,7,7hexachlorobicyclo(2.2.1) S-heptene-Z- acetic acid present at aconcentration of 5 p. p. in. reduced the growth of the pea sections byabout 60%. In

6 the high toxicity of this material plant tissue.

As further examples of the invention, a number of tests were carried outwherein selected plant regulators towards this living contrast,2,4-dichlorophenoxyacetic acid and 2,5-dichloro- 5 of the invention wereapplied to various species of plants benzolc acid are seen fromexperiments 3 and 4 comand the action on the plant observed. The testswere pared with experiment 1 to have increased the growth by carried outby preparing solutions or suspensions of the about 75% and about 24%,respectively. In addition to test material in a suitable horticulturalcarrier and spraythe diiferent action thus evidenced by experiments 1 toing measured amounts of the solution or suspension onto 4, experiments 5and 6 show that l,4,5,6,7,7-hexachloro- 10 the aerial parts of theplant, with observation of the b1cyclo(2.2.l)-5-heptene-2-acetic acidcompletely abolcondition of the plant at an appropriate interval afterished the growth stimulation induced by 2,4-dichlorothe sprayapplication. Illustrative examples of the invenphenoxyacetic acid and2,5-dichlorobenzoic acid, evidenction as thus carried out are shown inTable IV. In each mg the antagonistic action between this plantregulator case control experiments were performed utilizing the of thepresent invention and these known auxin-like masame spray compositionless the listed active component. tenals. In all cases, no adverseeffects were observed in the con- Example 48.In a fourth group ofexperiments, the trol experiments; the results shown in the table thusare action of 1,4,5,6,7,7-hexachlorobicyclo(2.2.l)-5-hepteneattributableto the presence of the active component Z-acetamidine hydrochloride uponthe living tissue of shown in the table.

TABLE IV Active component Ex. Carrier, or formulation of N o.Concenspray Test plant Results Chemical name tration, percent w.

49 l,4,5,6,7,7-hexachlorobicyclo- 2 Xylene, 10 volumes, diesel Maturefield-grown cotton Induced defoliation. Some(2.2.1)-5-heptene-2-carboxylic oil, 10 volumes, active (Acala 4-42), San.loafoliage burn. acid, M. P. 176l78 0. component and emulsiquin Valley,California.

fier (ca. 1%) emulsified in water to make 100 parts by volume.

50 1,4,5,6,7,7-hexachlorobicyolo- 8 do Paradox Walnut, year-old Induceddefoliation.

(2.2.1)-5-heptene-2-acetic acid nursery stock.

51 do 2 do Maturefield-grown cotton Induced defoliation, with (Acala4-42), San 1021- high percentage of green quin Valley, California.leaves abscised.

52 do 1 do Mature field-grown ramie Induced defoliation.

(Boehmeria m'vea), San Joaquin Valley, California.

53 do 8 do Plum trees, year-old nurs- Induced autumn coloraery stock.tion accompanied by leaf op.

54 do 2-8 do Black walnut trees, prune Induced defoliation, with trees,peach trees, 21- some damage to branches mond trees. All yearat thehigher concentra old nursery stock. tions.

55 l,4,5,6,7,7-hexachloro-B-methyl- 4 10% diesel oil, active com-Bermuda grass, field Killed oif aerial parts of the bicyclo(2.2.l)-5-heptene -2-carponent and emulsifier e grown. grass. boxylic acid.(ca. 1%) emulsified in water to make 100 parts by volume.

56 1,4,5,6,7,7-hexaehlorobicyclo- 0.5 Acetone solution of active Oats,greenhouse grown.-. Selectively toxic to oats(2.2.1)-2,5-heptadienylmethylagent dispersed inwater sprayed togetherwith malonic acid. with aid ofwater-soluble cotton seedlings.

57 Ammonium 1,4,5,6,7,7-hexachloro- 0.2 Water containing 0.1% Maturefield-growncotton Induced defoliation.

bicyclo(2.2.1)-5-heptene-2- Aerosol OT as wetting (Acala 442), SanJoaacetate. agent. quin Valley, California.

58 l,4,5,6,7,7-hexachlorobicyclo- Acetone solution of active Oats,greenhouse grown... Selectively toxic to oats(2.2.1)-5-heptene-2-carboxamide. agent dispersedinwater sprayed togetherwith with aid of water-soluble cotton seedlings. emulsifier.

59 N-brom0-1,4,5,6,7,7-hexachloro- 0.12 odo Toxic to oats.

bicyclo(2.2.l)-5-l1eptene-2-carboxamide.

60 Methyl 1,4,5,6,7,7 -hexachloro- 0.25 do Cotton seedlings, green-Induced defoliation.

alpha-hydroxybicyclo(2.2.1)-5- house grown. heptene-Z-acetate.

I Equal amounts of B1956 and Triton X-100.

b Santomerse.

Elodea densa was determined. The experiments were carried out byimmersing isolated leaves of the test plant in distilled watercontaining the test material. After standing immersed in the testsolution for about 6 hours in diifused light and then about 12 hours inthe dark, in both cases at ambient temperatures, the individual cells ofthe leaf were examined through an oil-immersion microscope, about 1000;:magnification. By observation of the cellular structure and protoplasmicmovements the effect of the test material upon the living cells wasdetermined. With 1,4,5 ,6,7,7-hexachlorobicyclo(2.2. l 5heptene-Z-acetamidine hydrochloride, toxicity evidenced bydisintegration of the intracellular structures and complete cessation ofprotoplasmic streaming was observed at a concentration cf 10 parts permillion, demonstrating chlorobicyclo 2.2.1 )-5-heptene-2-acetic acid.

Example 61.In field tests using one of the plant regulators of theinvention as a cotton defoliant, mature cotton (variety Acala 4-42)growing in the San Joaquin Valley of California was treated with1,4,5,6,7,7-hexa- Plots of approximately one acre were selected for thetests, with the cotton bearing a heavy opened boll load. In each of thetest plots, approximately 75 plants were selected at random and taggedfor leaf counts. Leaf counts were made both before spraying and twoweeks after spraying. The sprays were applied by helicopter equippedwith a commercial spray rig, flying at about 65 miles per hour. The rateof application was varied by means of the rate at which the helicoptertraversed the field and by adjustment of the spray apparatus. A con-,centratewas-prepared containing 36%"w.:of 1,4,5,-6,7,7-hexachlorobicyclo(2.2.l)--heptene-2-acetic acid, 5% :w. of Emcol H.-65C;(a commercial sulfonate emulsifying agent sold by Emulsol Corporation),5% w. of the butyl monoether f ethylene glycol, and 54% .of a lightpetroleum distillate as solvent. The final spray was :made .up by.diluting the concentrate with sufiicient water to .give a concentrationof l,4,5,6,7,,'7.-hexachlorobicyclo,(-2.2.;l)-5-heptene 2-acetic .acidof 0.5 :polmd per gallon of emulsion. For comparison, one plot wassprayed with a .commercial sodium chlcrate-borate defoliant .(Ortho Cl)at the dosage rate ,of ,12,gallons per acre recommended by themanufacturer. The .results observedare shown .in the followingtablc.

TABLE -v I Rate of application Initial leaves per plant Gallons of sprayper acre Pounds of activernaterial per acre Active material applied payer plioation None 1, 4, 5, 6, 7, 7 -hexachlorobicy- 010 (2.2.1)-Y5-heptene-2-acetic aci 8 5 Sodium chlorate-borate The treatment withthe l,4,5,6,7,7-hexachlorobicylclo- (2.2.1)-5-heptene 2-acetic acidcaused no visible staining or other injury to the cotton bolls. Thecotton plants were uninjured, except for the desired defoliation, and ina condition suitable for harvesting the cotton by mechanical pickers.The fact that young, as well as mature, leaves had been abscised by thetreatment with 1,4,5 ,6,7,7 hexachlorobicyclo(2.2. 1 -5-heptene 2.acetic acid was a pronounced advantage .in this respect because of thenegligible chlorophyll-stain of the cotton during mechanical picking.

The plant regulators that are employed in the novel compositions of thisinvention comprise broadly the substituted aliphatic carboxylic acidsand the anhydro derivatives of the same, wherein the symbol BCHrepresents a bicyclic, unsaturated, fusedring, carbocyclic, heptatomicring or nucleus, the symbol R represents a divalent aliphatic radicalone valency of which is satisfied by the group BCH and the other valencyof which is satisfied by the carboxyl group, and n represents eitherzero (0) or one (1).

The bicyclic ring represented by BCH may contain but one nuclearunsaturated linkage, or it may contain more than one. In the preferredplant regulators of the invention there is present-not more than onenuclear unsaturated linkage in the groupage BCH. The ring system BCH maybe subtituted by one or more hydrocarbon groups, such as the phenylgroup or a substituted phenyl group, e. .g., .tolyl or xylyl, or analkyl group, such as methyl, ethyl, propyl, ispropyl, a butyl group, orthe like. It has been found that substitution of halogen on the bicyclicring represented by BCH greatly and unexpectedly enhances thephysiological effects of these new plant regulators upon plants. In thepreferred compositions of the invention the active component willcontain as the substituent group BCH one exclusively composed orconsisting .of the elements carbon, hydrogen, and halogen, ,preferablybromine or chlorine.

As has been made abundantly clear by the examples, the active componentsof the compositions of this in- :vention may have the carboxyl grouprepresented by TCQOH in the foregoing generic formula (or the functionalgroup derived therefrom by anyhydrosynthesis) directly substituted ,on:thebicyclic ring system of the ,group iBCH, .or .the GOO,H ,orfunctionally related group may be bonded to the ring system rt rq gh 1;

te v n s al nha roup -R- h. ph i 19. may the s t a d un a u a d. a is so by he ex mp e and t may b Substituted o u u uted- Substituents whichmay be present on the said aliphatic oup i c de mong ot e e y o g up tse boxyl group, one or more atoms of halogen, e. g, bromine, chlorine,or fluorine, ester groups OOOR and .-..C.O. OR wherein R represents analkyl, aryl, .-.-y .l a syl l nY1 m les g up the d y a se, other groupsR wherein R represents an alkyl, ,aryl, cyoloalkyl, ,alkenyl, orarallcyl groups, etc. Other things being equal, the number of atomsdirectly intervening between the group BCH and the carboxyl orfunctionally related group influences to a considerable extent the.phytophysiological activity. Although useful compositions of theinvention may contain active components wherein as many as eight atomsdirectly intervene .between the carboxy .or functionally related groupand the group BCH, the most valuable compositions are those whereinthere are not more than three intervening atoms. outstandingly effectiveas defoliants for cotton, for such orchard crops as peaches, plums,prunes, walnuts, and the like, .as Wellas various nursery stock, are theregulators of the inventionwherein n in the foregoing formula representseither 0 or 1 and R represents a methylene or ethylene group or anoxy-substituted methylene or ethylene group. For cotton defoliation, themost effective regulators of the invention appear t0 the those whereinRrepresents a methylene group, that is to say, the acetic acidderivatives included by the foregoing formula.

It generally is preferred to employ as the active com- :ponent of thecompositions of the invention either the acid per se, represented by theforegoing formula, or an ionizable anhydro derivative thereof, such asan alkali metal or ,alkaline earth metal salt. When applied to thefoliage of mature plants, which in almost all cases will comprise anouter layer or Waxy cuticle that is more or lessimpervious topenetration .by low molecular weight solutes from aqueous solutions,these highly polar materials appear to penetrate into the leaf tissues mre readily than do the less polar derivatives, with the result thattheir hormonal action is more effectively exerted. Where .ease ofpenetration is not a factor, owing to immaturity of the plant or to thespecies of plant, the [relatively nonpolar as well as the polarderivatives may be employed quite effectively.

A preferred group of the plant regulators of this invention may bedefined as having structures represented by wherein each X represents anatom of'halogen, preferably bromine .or chlorine and most desirablychlorine, Y represents the ghydrogen atom or an atom .of halogen,preferably bromine orchlorine and most desirablychlorine, R' representsan alkylene group of from 1 to 3 carbon .atoms, a hydroxy-substitutedalkylene group of from .-1 to 3 carbon atoms, or a halogen-substitutedalkylene groupof from 1 to 3 carbon atoms, each R and R represents thehydrogenatom or an alkyl group of from ,lito .4 carbon-atoms, Drepresents anoxygen atom or NH, E represents :hydroxy, alkoxy,aminoalkoxy, metalloxy, .aryloxy, .and amino (including N-substitutedamino) gr oups. Of these, the preferred active agents-willcoh- .tain butone .do ble bond in the bicyclic ring structure (m represents ,thenumeral 1). With respect todcfoliaofcotton, the ,most active materialsof preferred group appear to be those wherein X and Y each representchlorine and the bicyclic ring structure is otherwise unsubstituted, Rrepresents methylene, ethylene, oxy-substituted methylene, oroxy-substituted ethylene, and the carboxyl group is present either assuch or in the form of a derived polar anhydro group, especially alkalimetal salt. Of these, 1,4,5,6,7,7-hexachlorobicyclo(2.2.1)-5-heptcne-Z-acetic acid and its alkali metal salts, such as the sodiumsalt, appear to be outstanding. The alkyl esters of this acid havingfrom 1 to 2 carbon atoms in the alkyl group are also highly effectivefor cotton defoliation.

Generally speaking, the active agents that are employed in theagricultural and horticultural compositions of the invention can beprepared by reacting a conjugated cyclopentadiene hydrocarbon orhalogen-substituted conjugated cyclopentadiene hydrocarbon with anethylenically or acetylenically unsaturated aliphatic carboxylic acid oranhydro derivative of such acid in the Diels-Alder manner to produce a1:1 adduct. In many cases, the desired product may be prepared directlyby reaction of the appropriate cyclopentadiene hydrocarbon orhalogen-substituted cyclopentadiene hydrocarbon. In other cases it maybe more convenient first to prepare a Diels-Alder 1:1 adduct of thecyclopentadiene hydrocarbon or halogen-substituted cyclopentadienehydrocarbon and the unsaturated acid or anhydro derivative thereof, andthen to convert this adduct by modification of the carboxyl or relatedfunctional group to obtain the desired product. Methods applicable tothe preparation of active components of the compositions of thisinvention are illustrated by the following examples.

Example I .J 4,5 ,6, 7,7 -lzexachlorobicycl- (2.2.1 -5- heptene-Z-aceticacid Vinyl acetic acid and hexachloro-1,3-cyclopentadiene reacted in theDiels-Alder manner and the product distilled and triturated with pentaneto purify. Melting point, 119-123 C.1,4,5,6,7,7-hexachlorobicyclo(2.2.l)-5-heptene-Z-acetic acid can also beprepared by acid hydrolysis of l,4,5,6,7,7hexachlorobicyclo(2.2.1)-5-heptene-2-acetom'trile prepared in theDiels-Alder manner from hexachloro-1,3-cyclopentadiene and allylcyanide.

Example II.-1,4,5,6,7,7-hexachZorobicyclo(2.2.1 )-5-heptene-Z-carboxylic acid Example III .-1,4,5,6,7,7-hexachl0robicyclo(2.2.1 -5- heptene-Z-pelargonic acidHexachloro-l,3-cyclopentadiene and lO-undecenoic acid reacted in theDiels-Alder manner and the product distilled (molecular still). Boilingpoint, 186-188 C. under 8x10 mm. mercury pressure. Refractive indexExample I V.] ,4,5 ,6 -tetrachl0r0bicyclo 2.2.] -5- heptene-Z-carboxylicacid l,2,3,4-tetrachloro-l,3-cyclopentadiene and acrylic acid reactedand the product fractionally crystallized utilizing successively hexane,hexane-ether, carbon tetrachloride, and nitromethane to yield twofractions, one melting at 157-158 C. and the other melting at 138-140 C.The two fractions represent different stereoisomers having the sameplanar structure.

Example V.-1,4,5,6,7,7-hexachl0r0bit7cl0(2.21)-.iheptene-Z-acrylic acidExample VI.-1,4,5,6-tetrachl0r0bicyclo(2.2.1 -5- heptene-2-acrylic acidPrepared in the manner described forl,4,5,6,7,7-hexachlorobicyclo(2.2.1)-5-heptene-2-acrylic acidsubstituting 1,2,3,4-tetrachloro-1,3-cyclopentadiene for the hexachloro-1,3-cyclopentadiene. Melting point -122 C.

Example VII.1,4,5,6,7,7-hexachl0r0bicycl0(2.2.1)-5- heptene-Z-propionicacid 1,4,5 ,6,7,7-hexachlorobicyclo(2.2. l -5-heptene-2-acrylic acidhydrogenated at about 45 C. and 40-50 p. s. i. hy-

drogen pressure, using platinum oxide catalyst. Melting point 84-845 C.

Example VIII.Bicycl0 (2.2.1 5-h eptene-Z-acetic acid Allyl cyanide and1,3-cyclopentadiene reacted in the Diels-Alder manner to producebicyclo(2.2.1)-5-heptene- 2-acetonitrile and this product hydrolyzed tothe acid. Boiling point 133-136 C. under 12 mm. mercury pressure.

Example IX .1 ,4,5 ,6,7, 7-hexach l0r0-3-methylbicycl0- (2.2.1-5-heptene-2-carboxylic acid Hexachloro-1,3-cyclopentadiene and crotonicacid reacted in the Diels-Alder manner and the product crystallized fromethyl acetate. Melting point 171172 C.

Example X .-1 ,4,5 ,6, 7,7-alpha,beta-octachlorobieyclo- (2.2.1)-5-heptene-2-propionic acid1,4,5,6,7,7-hexachlorobicyclo(2.2.1)-5-heptene-2-acrylic acidchlorinated in carbon tetrachloride solution by reaction with chlorinegas. Melting point 192-194 C.

Example Xl.-Bicycl0(2.2.] )-5-heptene-2-carboxylic acid Cyclopentadieneand acrylic acid reacted in the Diels- Alder manner. Boiling point 8994C. under 0.7-0.8 mm. mercury pressure.

Example XII.1,4,5,6,7,7-hexachlor0bicycl0(2.2.1 -2,5- heptadienylmethylmalonic acid Example XIII .S0diam 1,4,5,6,7,7-hexachlorobicyclo- (2.2.1)-5-heptene-2-acetate 1,4,5,6,7,7-hexachlorobicyclo (2.2. 1-5-heptene-2-acetic acid dissolved in the equivalent amount of 2.5% w.aqueous sodium hydroxide solution and product crystallized by chilling.

Example X I V.S0diam bicycl0(2.2.1 -5- heptene-Z-acetateBicyclo(2.2.l)-5-heptene-2-acetic acid neutralized by reaction with theequivalent amount of aqueous sodium hydroxide solution.

Example X V.Sodium (2.2.1 )-5-hepzene-Z-carboxylate l,4,5,6,7,7hexaclzlorobicyclo 11 2.5% W. aqueous sodium hydroxide solution and theproduct crystallized by chilling. Solubility of sodium l,4, 5,6,7 ,7hexachlorobicyclo(2.2.1) 5 heptene 2- carboxylate in water at 17 C., ca.111 grams per liter.

X VI .-A mmonium 1,4,5,6,7,7-hexachlorobieyclo (2 .2 .1 )-5-heptene-2-earboxylate Solid 1,4,5 ,6,7,7-hexachlorobicyclo(2.2. l-5-heptene-2- carboxylic acid triturated on the steam bath with LN-aqueous NH4OH. The salt was insoluble in benzene, hexane and ether;moderately soluble in water and acetone.

Example Example X VII .-Ptassiam 1,4,5,6,7,7-hexachloi'obicycle- (2.2.1--heptene-2-carb0xylate 1,4,5,6,7,7-hexachlorobicyclo(2.2.1) 5 heptene2- carboxylic acid dissolved in a calculated amount of 7% w. aqueous KOHsolution and the product crystallized by evaporation and cooling.

XVIIl.-Zinc 1,4,5,6,7,7 hexachlorobicyclo- Example(2.2.1)-5-heptene-2-carb0xylate Zinc chloride added to an equeoussolution of sodium l,4,5,6,7,7 hexachlorobicyclo(2.2.-l) 5 heptene 2-carboxylate to precipitate the insoluble zinc salt.

Example XIX.--N-(2-hydroxyethyl) amm0niam-1,4,5,6.- 7,7-h exae'hlorobicyelo (2 .2 .1 -5-heptene2-carb o'xylate Ethanolamine and1,4,5,6,7,7 hexachlorobicyclo (2.2.1)-5-heptene-2-carboxylic acidreacted in equimolar amounts and the product washed with hexane andether and then dried. Melting point 143-144 C.

XX.Hydraziniam 1,4,5,6,7,7hexachl0r0bi cyclo(2.2.1)-5-heptefie-2-carb0xylate Example l, 4,5,6,7,7 hexachlorobicyclo(2.2.l)5 heptene 2- carboxylic acid and hydrazine hydrate reacted inequirnolarproportions in diisopropyl ether solution. Melting point afterrecrystallization from methanol-chloroform mixture, 173'176 C.

Example XXL-Methyl 1,4,5,6-tetrachlorobicyclo(2.2.1)-5heptene-2-carb0xylate XXII.Butyl 1,4,5,6,7,7 hexachlorobicyclo- (2.2.1)-5-heptene-2-carb0xylate Example l,4,5,6,7,7 hexachlorobicyclo(2.2.1) 5heptene 2- carboxylic acid converted to the acid chloride by reactionwith sulfurous oxychloride and the acid chloride reacted with butylalcohol to yield the ester. Boiling point 126-150 C. under 0.1 mm.mercury pressure.

Example XXIIl.-2 acetamidoethyl 1,4,5,6,7,7 hexachlor0bicycl0(2.2.1)-5-heptene-2-carb0xylate N-acetcethanolamine and the acid chloride of1,4,5,6,- 7,7-hexachlorobicyclo(2.2.1)-5-heptene-2-carboxylic acidreacted in refluxing benzene.

Example XXIV.2 diethylaminoethyl 1,4,16,77,7- hexachl0r0bicycl0(2.2.l-5-hepterze-2-carhoxy'late 2-diethylaminoethanol and the acidchloride'of 1,4,5,- 6,7,7 hexachlorobicyclo(2.2.l) 5 heptene 2 car-'boxylic acid reacted in pentane solution and product distilled afterfiltering off the precipitated Z-diethylaminoethanol hydrochloride salt.Boiling point of redistilled product, l60165 C. under 0.2 mm. mercurypressure.

12 Example XX V.-Ethyl 1,4,5,6,7,7 hexachlorobicyclo- (2.2.1-5-heptene-2-acetate Hexachloride-l,3-cyclopentadiene and allyl cyanidereacted in the Diels-Alder manner to produce 1,4,5,6,7, 7-hexachlorobicyclo(2.2.1)-5-heptene-2-acetonitrile and the nitrilereacted with absolute ethanol (sulfuric acid catalyst) to yield theester. Boiling point -133 C. under 0.4 mm. mercury pressure.

Example XXVI.-1,4,5,6,7,7 hexachl0r0bicycl0(2.2.1)-5-zeptene-Z-aeetamidine hydrochloride 1,4,5,6,7,7hexachlorobicyclo(2.2.1) 5 heptene 2- aceto-nitrile in ether solutiontreated with hydrogen chloride and ethanol and the resulting ethyl1,4,5,6,7,7+ hexachlorobicyclo(2.2. 1 -5-heptene-2-acetimidatehydrochloride reacted with ammonia.

Example XXVII.-Ethyl 1,4,5,6,7,7-hexachl0r0hicyclb(2.2.1)-5-heptene-Z-acetimidate hydrochloride Melting point C.(decomposition).

Example XXVIIL-Ethyl l,4,5,6,7,7-hexachlorobicyclo- (2.2 .1)-5-heptene-2-acetimidate hydrobromide Prepared by reaction of1,4,5,6,7,7-hexachlorobicyclo (2.2.1)-5-heptene-2-acetonitrile withethanol and hydrogen bromide. Melting point 144l45 C. (decomposition).

Example XXlX.-Isopr0pyl 1,4,5,6,7,7-hexachl0r0bicy- Cl0-(2.2.1-5-heptene-2-acetimidate Prepared by reaction of1,4,5,6,7,7-hexachlorobicyclo- (2.2.1)-5-heptene-2-acetonitrile withisopropyl alcohol and hydrogen chloride. Melting point ISO-151 C.(decomposition) Example XXX.Methyl l,4,5,6,7,7-hexachlorbbicyclo- (2.2.1)-5-heptene-2-acetimidate hydrochloride Prepared by reaction of1,4,5,6,7,7-hexachlorobieyclo- (2.2.1)-5-heptene-2-acetonitrile withmethanol and hydrogen chloride. Melting point 123125 C. (decomposition).

Example XXXl.Ethyl 1,4,5,6,7,7-hexachl0rabicycl0- (2.2.1-5-heptene-2-carb0ximidate hydro'brom'ide Prepared by reaction of1,4,5,6,7,7-hexachlorobicyclo- (2.2.1)-5-heptene-2-nitrile with ethanoland hydrogen bromide. Melting point 111 C. (decomposition).

Example XXXIl.--( 1.,4,5,6,7,7-hexachl0robicyclo(2 .2 .1

' S-heptene-Z-yl-methylehe)malononitrile Prepared by modified Doebnerreaction between i'n'alononitrile and1,4,5,6,7,7-hexachlorobicyclo(2.2.l)-5- hptene-Z-carboXaldehyde. Meltingpoint 1141l5 C.

Example XXX V.Ethyl 1,4,5,6-tetraehl0r0-alphacyan0bicycl0(2.2.1)-5-heptene-2-acrylate 1,4,5,6-tetrachlorobicyclo(2.2.1)-5-heptene-2carboxaldehyde reacted with ethyl cyanoacetate.

Example XX X VI .1 ,4,5 ,6 ,7,7-hexachlorabic'yclo- (2.2.1)-5-heptene-Z-acryloniifile 1,4,5,6,7,7 hexachlorobicyclo(2.2.1) 5heptene=2- carboxaldehyde reacted with cyanoacetic acid by modifiedPerkin condensation. Melting'point 1 -22-12'2-.S C,

7 13 Example XXX VII.1,4,5,6,7,7-hexachlr0bicycl0- (2.2.1-hepzene-2-carb0xamide Melting point 161-162 C.

Example XXX VIII.1 ,4,5,6,7,7-hexachlorobicyclo- (2.2.1-5-heptene-2-carb0xylic anhydride Methyl 1,4,5,6,7,7-hexachlorobicyclo(2.2. 1 -5-hep tene-2- carboxylate, meltingpoint 5760 C.

Ethyl l,4,5,6,7,7 hexachlorobicyclo(2.2.l) 2,5 heptadiene-Z-carboxylate,boiling point 116-120 C. under 0.2. mm. mercury pressure Methyll,4,5,6,7,7-hexachlorobicyclo(2.2.1) 2,5 heptadiene-Z-carboxylate,melting point 86.587 C.

Methyl 1,4,5,6,7,7-hexachloro 2 methylbicyclo(2.2.1)-

S-heptene-Z-carboxylate, melting point 81-82" C.

Decyl l,4,5,6,7,7 hexachlorobicyclo(2.2.1)-5-heptene-2- carboxylate,boiling point 190-195 C. under 0.3 mm. mercury pressure p-Chlorophenyl1,4,5,6,7,7 hexachlorobicyclo(2.2.l) 5- heptene-Z-carboxylate, meltingpoint 104.5106 C.

Methyl l,4,5,6,7,7-hexachlorobicyclo(2.2.1)-5-heptene-2- acetate,boiling point 118-143 C. under 0.08 mm. mercury pressure Decyl1,4,5,6,7,7 hexachlorobicyclo(2.2.1)-5-heptene-2- acetate, boiling point162 C. under 0.0005 mm. mercury pressure l,4,5,6,7,7hexachlorobicyclo(2.2.1) 2,5-heptadiene-2- carboxylic acid, meltingpoint 205-2l0 C. (decomposition) The novel plant regulator compositionsof this invention comprise one or more of the phytophysiologicallyactiveacids or anhydro derivatives thereof dissolved or suspended in orcarried by an appropriate horticultural carrier. According to theintended method of application and the species of plant and the type ofplant tissue, the novel compositions may be formulated as solutions inwater or a suitable organic solvent, as dispersions or emulsions of theactive agent in a non-solvent therefor, as emulsions of a solution ofthe active agent in a suitable solvent emulsified with a second,inhomogeneous liquid, or as solids comprising the active agent or agentssorbed on a sorptive solid carrier.

It has been discovered that where the compositions of the invention areto be applied to mature plants, as for defoliating cotton and otherleafy agricultural crops or nursery stock, the composition desirablyshould contain one or more organic solvents, preferably a hydrocarbonsolvent of relatively high aromaticity. In addition to its normalfunction of serving as solvent for the active agent or agents and alsoproviding a readily applied liquid composition, the relatively aromaticsolvent markedly enhances the activity of the agents of the invention,apparently by facilitating penetration of the waxy outer layer of theleaf by the active agent. The aromatic solvent may be a highly refinedaromatic hydrocarbon, such as benzene, toluene, xylene, ethyl benzene,cumene or isodurene, or it may be a less highly refined relativelyaromatic hydrocarbon mixture, such as a coal tar fraction, astraight-run petroleum distillate, a thermally or catalytically crackedhydrocarbon oil, platformate or the like. Suitable solvents may alsocomprise a relatively aromatic solvent blended with a substantiallyaliphatic or naphthenie solvent such as a refined gas oil, lightlubricating oil, refined kerosene, mineral seal oil and the like.

Although the solvent usually will be of mineral origin, oils of animalor of vegetable origin may also be employed in or as the carrier. Inappropriate cases oxygenated solvents, such as alcohols, e. g.,methanol, ethanol, isopropyl alcohol, n-butyl alcohol, and amyl alcohol,ketones, such as acetone, methyl ethyl ketone, methyl 1 4 isobutylketone, etc., glycols and glycol ethers, and chicrinated solvents may beemployed as the carrier.

Where a hydrocarbon oil is used as the carrier, it preferably will beone which boils between about 300 F.

and about 800 F. and desirably will have a viscosity not over about 60S. S. U. at F. The relatively aromatic carrier preferably will have anaromatics content upwards from about 20% by volume by sulfonation,although it will be understood that solvents of a lesser degree ofaromaticity may be employed. When used for defoliation of cotton, thecarrier, of course, should be one which does not lead to undesirablestaining of the open cotton .bolls.

Solutions of the active agents may be applied as such to the plants orto the soil that is to be treated, as, for example, for herbicidalpurposes, or they may be suspended in water and the suspension oremulsion applied to the plants or soil. Thus, a relatively concentratedsolution of the active agent in a water-immiscible solvent may beprepared, with added emulsifying, dispersing or other surface activeagents, and the concentrate diluted in the spray tank with water to forma uniform fine emulsion which can be applied by conventional spraydevices. Emulsions or dispersions of the active agents as such in watermay also be prepared and applied.

The invention includes novel solid compositions of matter wherein theactive agent or agents are absorbed or adsorbed in or on a sorptivecarrier, such as finely divided clay, talc, gypsum, lime, wood flour orthe like. The solid composition, or dust, may contain from as little as1% by weight of active material to 60% by weight or more. It may beprepared in the form of a dust, or as granules designed to be broadcastor to be worked into the soil, as for herbicidal purposes. Wettablepowders can be prepared suitable for suspension in water with or withoutthe aid of conventional dispersing or deflocculating agents and with orwithout such adjuvants as oils, stickers, Wetting agents, etc.

Suitable emulsifiable concentrates, adapted for dispersion in water toprovide a sprayable composition, ordinarily will contain between about10% w. and about 50% w. of active agent dissolved in a hydrocarbon orother suitable water-immiscible solvent. Minor amounts, say from about/z% w. to about 10% w. of emulsifying agents may be included to promotedispersion of the concentrate in water. Suitable emulsifying agents arepreferably oil soluble and include, among others, alkaryl sulfonates,sulfates of long chain fatty alcohols, amides, such as N-hydroxyalkylamides of long chain fatty acids, alkylaryl polyoxyethylene glycolethers, sulfonated White oils, sorbitan esters of long chain fattyacids, alkylamide sulfonates and the like.

Liquid compositions of this invention, suitable for application toplants or their environment, contain the active agent or agents inconcentrations generally within the range of from about 0.01% by weightto about 25% by weight. For purposes of defoliation, as, for example,cotton, the preferred compositions of the invention contain l,4,5,6,7,7hexachlorobicyclo(2.2.1) 5-heptene-2- acetic acid or an alkali metalsalt thereof as the active ingredient, at a concentration preferablybetween about 3% and about 10% by weight of the spray composition.Although not essential to the invention, the effectiveness of suchemulsions can be increased significantly by using as the aqueous phasean alkaline aqueous medium. The aqueous phase of the emulsion thus maycontain a strong alkali, such as sodium hydroxide, potassium hydroxide,or the like, in concentrations equivalent to from about 0.05 to about 1%w. NaOH, with a pronounced enhancement of activity compared to theemulsions without alkali.

For field application, the rate of application of the active agent maybe varied from about 0.5 to 30 or more pounds per acre. For example, anemulsion comprising 0.5 pound of active agent per gallon applied at the.rate of 6.5 gallons per acre will give a dosage of 3.2 pounds 494,276,Samuel B.

active agent-per acre. For defoliation of cotton, suitable rates ofapplication off'the compositions of this invention generally will be therange of from about 2 to about-8 pounds of active agentper acre,although it will be appreciated that these rates are subject tovariation according .to the local conditions, for example, temperature,humidity, moisture content of the soil, kind and condition of the plant,etc. For herbicidal purposes, higher rates of application, to as much as50 pounds or more per acre, may be employed.

Although primarily useful for inducing defoliation of deciduous plants,trees, and shrubs, the compositions of this invention are not restrictedin utility to this applica tion. They may be applied during the laterreproductive stages of celery, tobacco,lettuce, corn, tomatoes, etc., inorder to regulate the flowering. Applied during the earlier stages ofdevelopment of the plant, they may be used to inhibit terminal growthand stem elongation and to reduce apical dominance. In the growing oforchard crops, such as peaches,.pears, prunes, apples, apricots and the"like, the compositions of the invention can be used to induceabscission of fruit, whereby increased quality of the remaining yield isobtained. The compositions of the invention also are useful for chemicaldeflowering. They also may be employed to control or reduce shootdevelopment, as on potatoes and other tuberous vegetables during storageor during storage and shipment of nursery cuttings ofornamental andother plants.

The compositions of this invention may contain one ormore of the activeagents disclosed herein as the sole active component, or they maycontain in addition there to other biologically-active substances. Otherplant regulators, such as naphthalene acetic acid, 2,4dichlorophenoxyacetic acid and the like, as well as insecticides, e. g.,DDT, endrin, dieldrin, aldrin, chlordane, systox, methoxychlor,rotenone, and pyrethrum, and fungicides, such as'copper compounds,ferbam, captan'and the like, may if desired be incorporated in thecompositions of the invenn'on.

Reference is hereby made to the copending applications of John F.Wikstrom, Jr., and Juan G. Morales, Jr., entitled Esters, Serial No.494,278, Samuel B. Soloway, entitled Halo-Substituted BicyclicAldehydes, Serial No. v Soloway, entitled Polyhalogeno Bicyclic Acids,Serial No. 494,277, and Samuel B. Soloway, entitled Halo-SubstitutedBicyclic Compounds, Serial No. 494,280, all filed March 14, 1955,wherein compounds and intermediates useful for purposes of thisinvention are described and claimed, the pertinent disclosures of saidcopending applications hereby being incorporated by reference.

It will be appreciated that while specific embodiments of the inventionhave been presented, numerous other specific embodiments will beapparent to those skilled in the art, and, therefore, that the inventionshould not be construed as being limited except as appears from thehereto appended claims.

We claim as our invention:

1. A plant regulator composition comprising as an active component in anamount sufiicient to effect the growth processes of living plants achemical compound having a structure represented by the formula whereineach X represents an atom of halogen, each Y represents one of the groupconsisting of hydrogen and halogen, R represents one of the groupconsisting of the -15 alkylene groupsof from 1 to 3 carbon atoms, thehydroxysubstituted alkylene groups of from 1 to 3 carbon atoms, and thehalogen-substituted alkylene groups of from l to 3 carbon atoms, each Rand R represents one of the group consisting of hydrogen and alkylgroups of from 1 to 4 carbon atoms, D represents one of the groupconsisting of O and NH, E represents one of the group consisting ofhydroxy, alkoxy, aminoalkoxy, metalloxy, aryloxy, and amino, n reprmentsone ofthe group'consistingof-O'and 1, both ms represent the same memberof the group consisting off) and 1, and as adjuvantahorticulturalcarrier therefor.

2. A plant regulator composition comprising as an active component in anamount sufiicient to effect the growth processes of living plants analiphatic carboxylic acid having substituted on the aliphatic acidresidue a bicyclic, unsaturated, cycloaliphatic, halogen-substituted,fused-ring nucleus comprising two fused pentatomic carbocyclic ringshaving three carbons in common, the nuclear carbons being bonded only tomembers of the group consisting of hydrogen, carbon and halogen, and asadjuvant a horticultural carrier therefor.

3. A plant regulator composition defined by claim 2 comprising as anactivecomponent an aliphatic c-arboxylic acid as defined in claim 2,having a plurality of atoms of halogen substituted on ring carbons ofthe said bicyclic fused-ring nucleus.

4. A plant regulator composition comprising as an active component in anamount sufficient to affect the growth processes of living plants ananhydro derivative of an aliphatic carboxylic acid having substituted onthe aliphatic acid residue a bicyclic, unsaturated, cycloaliphatic,halogensub'stituted fused-ring nucleus comprising two fused pentatoinic'carbo'cyclic rings having three carbons in common, the nuclear carbonsbeing bonded only to members of the group consisting of hydrogen, carbonand halogen, and as adjuvant a horticultural carrier therefor.

5. A plant regulator composition defined by claim 4 comprising as anactive component an anhydro derivative as defined in claim 4 having aplurality of atoms of halogen substituted on ring carbons of the saidbicyclic fusedring nucleus.

6. A plant regulator composition defined by claim 4 wherein the saidanhydro derivative is a salt.

7. A plant regulator composition defined by claim 4 wherein the saidanhydro derivative is an ester.

8. A plant regulator composition defined by claim 4 wherein the saidanhydro derivative is an imido-ether mineral acid salt.

9. A plant regulator composition comprising as an active component in anamount sufiicient to effect the growth processes of living plants al,4,5,6,7,7-hexachlorobicyclo(2.2.l)-5-heptene-2-alkanoic acid and asadjuvant a horiticultural carrier therefor.

10. A plant regulator composition comprising as an active component inan amount sufficient to effect the growth processes of living plantsl,4,-5,6,7,7-hexachlorobicyclo('2.2.l)-5-heptene-2-acetic acid and asadjuvant a horticultural carrier therefor. V 11. A horticulturalcomposition comprising a solution of 1,4,5,6,7,7hexachlorobicyclo(2.2.1) 5 -heptene-2- alka'noic acid in an aromaticsolvent therefor at a concentration suihcient, upon dispersion of thecomposition in water and application of the dispersion to plants, toaffect the growth processes of such plants, and an emulsitying agentadapted to promote dispersion of the solution in water.

12. An emulsion comprising a composition defined by claim 11 dispersedin water.

13. A horticultural composition defined by claim 11 comprising as anactive component 1,4,5,6,7,7'-heiiachlorobicyclo 2.2. l)'-5-heptene-2-acetic acid.

14. An emulsion comprising a composition defined by claim 13 dispersedin water.

au ingn E i i wherein each X represents an atom of halogen, each Yrepresents one of the group consisting of hydrogen and halogen, Rrepresents one of the group consisting of the alkylene groups of from 1to 3 carbon atoms, the hydroxy-substituted alkylene groups of from 1 to3 carbon atoms, and the halogen-substituted alkylene groups of from 1 to3 carbon atoms, each R and R represents one of the group consisting ofhydrogen and alkyl groups of from 1 to 4 carbon atoms, D represents oneof the group consisting of O and NH, E represents one of the groupconsisting of hydroxy, alkoxy, aminoalkoxy, metalloxy, aryloxy, andamino, n represents one of the group consisting of and 1, both msrepresent the same member of the group consisting of 0 and 1.

16. The method of regulating growth processes of living plants whichcomprises bringing into contact with the plant in an amount sufficientto effect the growth processes of the plant an aliphatic carboxylic acidhaving substituted on the aliphatic acid residue a bicyclic,unsaturated, cycloaliphatic, fused-ring nucleus comprising two fusedpentatomic carbocyclic rings having three carbons in common, the nuclearcarbons being bonded only to members of the group consisting ofhydrogen, carbon and halogen.

17. The method of regulating growth processes of plants which comprisesbringing into contact with the plant tissue in an amount suflicient toaffect the growth processes of the plant tissue an anhydro derivative ofan aliphatic carboxylic acid having substituted on the aliphatic acidresidue a bicyclic, unsaturated, cycloaliphafic, fused-ring nucleuscomprising two fused pentatomic carbocyclic rings having three carbonsin common, the nuclear carbons being bonded only to members of the groupconsisting of hydrogen, carbon and halogen.

18, In the defoliation of living plants, the method which comprisesapplying to the foliage thereof a 1,4,5,6,7,7-hexachlorobicyclo(2.2. l)-5-heptene-2-alkanoic acid in an amount sufiicient to inducedefoliation by the plant.

19. In the chemical defoliation of living cotton plants, the improvementwhich consists of inducing defoliation by applying to the foliage of thecotton plants an amount of 1,4,5 6,7,7-hexachlorobicyclo( 2.2. 1-5-heptene-2-acetic acid suificient to induce defoliation thereof.

References Cited in the file of this patent UNITED STATES PATENTS

1. A PLANT REGULATOR COMPOSITION COMPRISING AS AN ACTIVE COMPONENT IN ANAMOUNT SUFFICIENT TO EFFECT THE GROWTH PROCESSES OF LIVING PLANTS ACHEMICAL COMPOUND HAVING A STRUCTURE REPRESENTED BY THE FORMULA